1 /* $OpenBSD: cmd-pipe-pane.c,v 1.51 2019/03/14 23:14:27 nicm Exp $ */ 2 3 /* 4 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER 15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/types.h> 20 #include <sys/socket.h> 21 22 #include <errno.h> 23 #include <fcntl.h> 24 #include <paths.h> 25 #include <signal.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <time.h> 29 #include <unistd.h> 30 31 #include "tmux.h" 32 33 /* 34 * Open pipe to redirect pane output. If already open, close first. 35 */ 36 37 static enum cmd_retval cmd_pipe_pane_exec(struct cmd *, struct cmdq_item *); 38 39 static void cmd_pipe_pane_read_callback(struct bufferevent *, void *); 40 static void cmd_pipe_pane_write_callback(struct bufferevent *, void *); 41 static void cmd_pipe_pane_error_callback(struct bufferevent *, short, void *); 42 43 const struct cmd_entry cmd_pipe_pane_entry = { 44 .name = "pipe-pane", 45 .alias = "pipep", 46 47 .args = { "IOot:", 0, 1 }, 48 .usage = "[-IOo] " CMD_TARGET_PANE_USAGE " [command]", 49 50 .target = { 't', CMD_FIND_PANE, 0 }, 51 52 .flags = CMD_AFTERHOOK, 53 .exec = cmd_pipe_pane_exec 54 }; 55 56 static enum cmd_retval 57 cmd_pipe_pane_exec(struct cmd *self, struct cmdq_item *item) 58 { 59 struct args *args = self->args; 60 struct client *c = cmd_find_client(item, NULL, 1); 61 struct window_pane *wp = item->target.wp; 62 struct session *s = item->target.s; 63 struct winlink *wl = item->target.wl; 64 char *cmd; 65 int old_fd, pipe_fd[2], null_fd, in, out; 66 struct format_tree *ft; 67 sigset_t set, oldset; 68 69 /* Destroy the old pipe. */ 70 old_fd = wp->pipe_fd; 71 if (wp->pipe_fd != -1) { 72 bufferevent_free(wp->pipe_event); 73 close(wp->pipe_fd); 74 wp->pipe_fd = -1; 75 76 if (window_pane_destroy_ready(wp)) { 77 server_destroy_pane(wp, 1); 78 return (CMD_RETURN_NORMAL); 79 } 80 } 81 82 /* If no pipe command, that is enough. */ 83 if (args->argc == 0 || *args->argv[0] == '\0') 84 return (CMD_RETURN_NORMAL); 85 86 /* 87 * With -o, only open the new pipe if there was no previous one. This 88 * allows a pipe to be toggled with a single key, for example: 89 * 90 * bind ^p pipep -o 'cat >>~/output' 91 */ 92 if (args_has(self->args, 'o') && old_fd != -1) 93 return (CMD_RETURN_NORMAL); 94 95 /* What do we want to do? Neither -I or -O is -O. */ 96 if (args_has(self->args, 'I')) { 97 in = 1; 98 out = args_has(self->args, 'O'); 99 } else { 100 in = 0; 101 out = 1; 102 } 103 104 /* Open the new pipe. */ 105 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) { 106 cmdq_error(item, "socketpair error: %s", strerror(errno)); 107 return (CMD_RETURN_ERROR); 108 } 109 110 /* Expand the command. */ 111 ft = format_create(item->client, item, FORMAT_NONE, 0); 112 format_defaults(ft, c, s, wl, wp); 113 cmd = format_expand_time(ft, args->argv[0]); 114 format_free(ft); 115 116 /* Fork the child. */ 117 sigfillset(&set); 118 sigprocmask(SIG_BLOCK, &set, &oldset); 119 switch (fork()) { 120 case -1: 121 sigprocmask(SIG_SETMASK, &oldset, NULL); 122 cmdq_error(item, "fork error: %s", strerror(errno)); 123 124 free(cmd); 125 return (CMD_RETURN_ERROR); 126 case 0: 127 /* Child process. */ 128 proc_clear_signals(server_proc, 1); 129 sigprocmask(SIG_SETMASK, &oldset, NULL); 130 close(pipe_fd[0]); 131 132 null_fd = open(_PATH_DEVNULL, O_WRONLY, 0); 133 if (out) { 134 if (dup2(pipe_fd[1], STDIN_FILENO) == -1) 135 _exit(1); 136 } else { 137 if (dup2(null_fd, STDIN_FILENO) == -1) 138 _exit(1); 139 } 140 if (in) { 141 if (dup2(pipe_fd[1], STDOUT_FILENO) == -1) 142 _exit(1); 143 if (pipe_fd[1] != STDOUT_FILENO) 144 close(pipe_fd[1]); 145 } else { 146 if (dup2(null_fd, STDOUT_FILENO) == -1) 147 _exit(1); 148 } 149 if (dup2(null_fd, STDERR_FILENO) == -1) 150 _exit(1); 151 closefrom(STDERR_FILENO + 1); 152 153 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL); 154 _exit(1); 155 default: 156 /* Parent process. */ 157 sigprocmask(SIG_SETMASK, &oldset, NULL); 158 close(pipe_fd[1]); 159 160 wp->pipe_fd = pipe_fd[0]; 161 if (wp->fd != -1) 162 wp->pipe_off = EVBUFFER_LENGTH(wp->event->input); 163 else 164 wp->pipe_off = 0; 165 166 setblocking(wp->pipe_fd, 0); 167 wp->pipe_event = bufferevent_new(wp->pipe_fd, 168 cmd_pipe_pane_read_callback, 169 cmd_pipe_pane_write_callback, 170 cmd_pipe_pane_error_callback, 171 wp); 172 if (wp->pipe_event == NULL) 173 fatalx("out of memory"); 174 if (out) 175 bufferevent_enable(wp->pipe_event, EV_WRITE); 176 if (in) 177 bufferevent_enable(wp->pipe_event, EV_READ); 178 179 free(cmd); 180 return (CMD_RETURN_NORMAL); 181 } 182 } 183 184 static void 185 cmd_pipe_pane_read_callback(__unused struct bufferevent *bufev, void *data) 186 { 187 struct window_pane *wp = data; 188 struct evbuffer *evb = wp->pipe_event->input; 189 size_t available; 190 191 available = EVBUFFER_LENGTH(evb); 192 log_debug("%%%u pipe read %zu", wp->id, available); 193 194 bufferevent_write(wp->event, EVBUFFER_DATA(evb), available); 195 evbuffer_drain(evb, available); 196 197 if (window_pane_destroy_ready(wp)) 198 server_destroy_pane(wp, 1); 199 } 200 201 static void 202 cmd_pipe_pane_write_callback(__unused struct bufferevent *bufev, void *data) 203 { 204 struct window_pane *wp = data; 205 206 log_debug("%%%u pipe empty", wp->id); 207 208 if (window_pane_destroy_ready(wp)) 209 server_destroy_pane(wp, 1); 210 } 211 212 static void 213 cmd_pipe_pane_error_callback(__unused struct bufferevent *bufev, 214 __unused short what, void *data) 215 { 216 struct window_pane *wp = data; 217 218 log_debug("%%%u pipe error", wp->id); 219 220 bufferevent_free(wp->pipe_event); 221 close(wp->pipe_fd); 222 wp->pipe_fd = -1; 223 224 if (window_pane_destroy_ready(wp)) 225 server_destroy_pane(wp, 1); 226 } 227